Tape actuated valve mechanism



Sept. 19, 1967 H MQRELLO 3,341,882

TAPE ACTUATED VALVE MECHANISM Filed June 30, 1965 VACUUM 26 2 25 12 25 HIGH PRESSURE INVENTOR 42 HERBERT MORELLO A T TORNE Y United States Patent 3,341,882 TAFE ACTUATED VALVE MECHANISM Herbert Morelio, Utica, N.Y., assignor to Sperry Rand Corporation, New York, N.Y., a corporation of Delaware Filed June 30, 1965, Ser. No. 468,497 7 Claims. (Cl. 306) ABSTRACT OF THE DISCLOSURE A tape actuated valve for a tape handling device is provided. A cylindrical tape guide member is mounted for rotation on a shaft and is positioned so that the tape threads over the guide element in frictional engagement therewith whereby movement of the tape will rotate the guide element in one direction or the other in dependence on the direction of tape movement. Stop means are provided to limit the rotation of the cylindrical guide element to some angle less than 180 degrees. A series of tape cleaning slits are formed in the surface of the guide element and are arranged so that in one direction of tape movement the slits will be moved into an engaging position with the tape, while when the tape is moved in an opposite direction the guide element is rotated so that the slits will be out of engagement with the tape.

This invention relates to valve mechanisms and, more particularly, to valve mechanisms for use in magnetic tape transport systems.

Valve mechanisms have taken numerous dilferent forms in the past in connection with tape transport systems. In the main, such mechanisms have been used to selectively connect a source of high or low fluid pressure to a tape to either cause it to engage or disengage a movable element, such as a rotating capstan. Such mechanisms have generally involved a relatively large number of precision parts. In addition, the mechanisms have also generally required electrical circuitry to actuate the movable parts.

It is an object of this invention to provide a novel valve mechanism.

It is a further object of this invention to provide an improved valve mechanism which may be actuated with a minimum number of parts.

It is still a further object of this invention to provide an improved valve mechanism which may be actuated to couple a source of high or low fluid pressure to a magnetic tape.

It is still a further object of this invention to provide an improved valve mechanism which may be selectively actuated to perform a cleaning operation on a moving magnetic tape.

In accordance with the present invention, a tape actua or low fluid pressure. A plurality of cutting elements are included on the cylindrical element in close proximity to the apertures to remove dirt particles from the tapes.

Other objects and advantages of the present invention will be apparent and suggest themselves to those skilled in the art, from a reading of the following specification and claims, in which:

FIGURE 1 illustrates a cross-sectional view of a valve mechanism, associated with a portion of a tape transport system illustrated by block diagrams;

FIGURE 2 is a view taken along lines 22 of FIG- URE l for one direction of tape movement;

FIGURE 3 is a view taken along a line 22 of FIG- URE 1 when the tape is being moved in an opposite direction, and

FIGURE 4 is a cross-sectional enlarged view illustrating cutting elements which may be used with the valve mechanism of the present invention.

Referring to the drawings, a valve mechanism 10 includes an outer cylindrical element 12 adapted to receive a magnetic tape 14. The cylindrical element 12 is disposed between a mounting member 16 and a cap member 18.

The mounting member \16 may be suitably mounted by any suitable means to a front panel 20 of a tape transport unit. The mounting member 16 includes a portion 17 extending through the front panel 20 and a shaft like portion 19 extending outwardly from the front panel parallel with the cylindrical element 12. The portion 19 provides a bearing surface as well as providing means for receiving a screw 22 to hold the cap member securely in place to the mounting member 16. The cylindrical element 12 is free to rotate on suitable bearings 25. The cap element 18, while held in place to the mounting member 16, is dimensioned so that it does not press against the cylindrical element so as to prevent the rotation thereof.

The mounting element 16 includes a bore opening 24 which leads into a chamber 26 through an aperture 21; The bore 24 may be connected to suitable conduits 27 and 28 which leads to a source of high or low pressure. For example, if the conduit 28 is connected to a source of low pressure or vacuum, the chamber 26 may be considered a vacuum chamber leading to various apertures to permit the tape 14 to be drawn toward the cylindrical element '12. If the conduit 28 is connected to a source of s relatively high fluid pressure and the cylindrical element um 30 or to a source of high pressure 32. The sources 30 and 32 are connected to the conduit 28 through a fluid ated valve is provided and comprises a cylindrical element I switching device 34. The latter switch 34 may be conventional one well known to those skilled in the art. In some cases, as in the preferred embodiment of the present invention, if it is desired to apply only a vacuum to the chamber 26, then the switching device 34 and the source of high pressure 32 would, of course, be unnecessary. Likewise, in other applications, if it is desired to apply only a high pressure to the chamber 26, the source of vacuum 30 and the switching device 34 would be unneces sary.

The mounting member 16 includes a pin element 36 which acts as a stop element for the cylindrical element for two directions of rotation. A portion of one side of Q the cylindrical element 12 is cut away with the pin 36 being disposed within the cut away portion. Without the pin element 36, the cylindrical element 12 would be free to rotate continuously about a full 360. The pin element 36, however, acts as a suitable element to limit the degree of rotation of the cylindrical element 12 to a rotation equal to the amount of the cut away portion. For example, it may be desirable to limit the degree of rotation of the cylindrical element 12 to approximately 90.

FIGURE 2 illustrates one position of the cylindrical element 12 being limited by the pin element 36. FIGURE 3 illustrates the position of the cylindrical element 12 when it has been rotated in a counter clockwise direction approximately 90".

One of the main features of the present invention resides in the fact that the magnetic tape 14 physically engages the cylindrical element 12 to cause it to rotate about a predetermined angle. When the tape 14 is moving toward the right, as illustrated in FIGURE 2, the friction between the tape 14 and the cylindrical element 12 causes the cylindrical element 12 to rotate until it engages the stop pin element 36. When the magnetic tape 14 is moving in the opposite direction, as illustrated in FIG- URE 3, the friction between the tape 14 and the cylindrical element 12 causes the cylindrical element 12 to be rotated in a counter clockwise direction until it engages the pin element 36. Thus it is seen that the direction of movement of the tape 14 will determine the position of the cylindrical element 12.

The movement of the cylindrical element 12 caused by the tape movement may be used to act as a valve, as a switching device, or for various other purposes in a tape transport system. For example, it may also provide a relatively simple means for detecting the direction and change in the direction of tape movement. It may also be used to detect changes in vacuum or pressure when out out portions (to be described) are moved out of contact with the tape and exposed to the atmosphere.

The cylindrical element 12 includes on a portion of its surface a plurality of cut-out areas to form cut-out areas 38 to form a plurality of cutting elements. The cutting elements comprise rectangle edges 44 and slightly rounded edges 46. A plurality of apertures 42 connect the cutout areas 38 into the chamber 26. It is noted that the cutout areas including the cutting elements and apertures extend throughout an angle substantially equal to the angle through which the cylindrical element 12 is free to rotate, that is approximately 90.

In a preferred embodiment of the present invention, it is desirable to clean the tape during normal operation, for example, when the tape is being moved toward the right. When the tape is moved toward the right, it engages edge portions 44. The relatively sharp 90 edges provide a slight degree of scraping permitting dirt and other foreign particles to be removed from the tape 14 without affecting any information stored on the tape. Any particles removed from the tape pass through the apertures 42 into a vacuum chamber 26. In preferred embodiments of the present invention, only a vacuum is used to perform a cleaning operation. Particles falling into the chamber 26 are carried away by the low pressure or vacuum. It is understood that the bottom surface of the tape, or the information bearing surface, may be cleaned.

During a rewind operation, the tape is moved toward the left. While the tape is still passing over the cutting edges during its initial reverse movement they are not subjected to a cutting action by the edges 44. The tape now engages the edges 46 which are somewhat rounded at the corners. The rounded corners provide a relatively smooth surface for the tape to minimize the degree of scraping action during the initial rewind operation.

After the initial rewind phase, the cylindrical element 12 is rotated approximately 90 and the cutting edges move out of contact with the magnetic tape. At this point, the magnetic tape 14 contacts only the smooth surface of the cylindrical element 12. Thus, no vacuum is applied to the tape and no cleaning operation takes place during rewind operation.

The present embodiment has illustrated the tape 14 being moved at right angles around the cylindrical element 12. While these directions may be ideal in many situations, it is apparent that lesser or greater angles may be involved. The important thing is that the contact between the magnetic tape 14 and the cylindrical element 12 provide sufficient friction to permit the cylindrical element 12 to be moved and therefore act as a valve mechanism.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a tape handler, the combination comprising; a shaft, a cylindrical tape guide member mounted for rotation on said shaft, a tape threaded over said guide member in frictional driving engagement therewith, said tape operating to rotate said guide member in one direction or the other in dependence upon the direction of movement of said tape, means limiting the degree of angular rotation of said guide member to an angle less than degrees, a series of slits formed in the surface of said guide member over an angle approximately corresponding to its angle of rotation, said slits being disposed to contact the tape during movement of the tape in one direction when the guide element has been rotated to one of its angular limit positions and to be out of contact with the tape during movement of the tape in the opposite direction when the guide element is rotated to its other angular limit position.

2. In a tape handler, the combination comprising; a shaft, a cylindrical tape guide member mounted for rotatation on said shaft, said tape guide member adapted to have a tape threadably passed thereover in frictional engagement therewith, the tape operating to rotate said guide member in one direction or the other in dependence on the direction of movement of the tape, means limiting the degree of angular rotation ofsaid guide member to an angle less than 180 degrees, a series of slits formed in the surface of said guide member over an angle approximately corresponding to its angle of rotation, said slits being disposed to contact the tape during movement of the tape in one direction when the guide element has been rotated to one of its angular limit positions and to be out of contact with the tape during movement of the tape in the opposite direction when the guide element is rotated to its other angular limit position.

3. In a tape handler; the combination comprising; a shaft, a hollow cylindrical tape guide member mounted for rotation on said shaft, a chamber formed between the guide member and said shaft, a passageway formed axially in said shaft, a bore hole interconnecting said passageway with said chamber, a tape threaded over said guide element in frictional driving engagement therewith, said tape operating to rotate said hollow guide member in one direction or the other in dependence upon the direction of movement of said tape, means limiting the degree of angular rotation of said guide member to an angle less than 180 degrees, a series of longitudinal slits extending through the surface of said guide member over an angle approximately corresponding to its angle of rotation, said slits being disposed to contact the tape during movement of the tape in one direction when the guide element has been rotated to one of its angular limit positions and to be out of contact with the tape during movement of the tape in the opposite direction when the guide element is rotated to its other angular limit position, and a fluid source coupled to the passageway of said shaft.

4. The structure as set forth in claim 3 wherein said fluid source comprises a vacuum.

5. The structure as set forth in claim 3 wherein said S iiS a e fQUIEd With edges for cleaning said tape and said fluid source comprises a vacuum whereby particles removed from said tape are carried away from said tape through said slits and said passageway.

6. The structure as set forth in claim 3 wherein the edges of said slits include perpendicular surfaces on one side of the slit and a curved surface on the other side of the slit.

7. The structure as set forth in claim 3 wherein said fluid source comprises a high pressure source.

References Cited UNITED STATES PATENTS Shue 15-100 DeYbarrando.

Brown.

Cleveland 15308 MacGregor 15375 X ROBERT W. MICHELL, Primary Examiner. 

1. IN A TAPE HANDLER, THE COMBINATION COMPRISING; A SHAFT A CYLINDRICAL TAPE GUIDE MEMBER MOUNTED FOR ROTATION ON SAID SHAFT, A TAPE THREADED OVER SAID GUIDE MEMBER IN FRICTIONAL DRIVING ENGAGEMENT THEREWITH, SAID TAPE OPERATING TO ROTATE SAID GUIDE MEMBER IN ONE DIRECTION OR THE OTHER IN DEPENDENCE UPON THE DIRECTION OF MOVEMENT OF SAID TAPE, MEANS LIMITING THE DEGREE OF ANGULAR ROTATION OF SAID GUIDE MEMBER TO AN ANGLE LESS THAN 180 DEGREES, A SERIES OF SLITS FORMED IN THE SURFACE OF SAID GUIDE MEMBER OVER AN ANGLE APPROXIMATELY CORRESPONDING TO ITS ANGLE OF ROTATION, SAID SLITS BEING DISPOSED TO CONTACT THE TAPE DURING MOVEMENT OF THE TAPE 